Portable grinder



Sept. 7 1926. 1,598,667.

C. F. WAITE I v PORTABLE GRINDER Filed Augus 9, 1921 4 sheets-Shag 1 INVENTOR.

"se i; 7 1926.

c. F. w'ArrE PORTABLE GRINDER Filed Augus t 9 1921 1 Sheets-Sheet 2.

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- c. F. WAITE PORTABLE GRINDER Sept. 7 1926 Sept. 7 1926. 1,598,667

c. F. WAITE PORTABLE GRINDER Filed August 9, 1921 4 Sheets-Sheet 4.

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Patented Sept. 7, 1926.

* UNITED STATES 1,598,667 PATENT orricE.

CHARLES F. WAI'IE, OF BOSTON, MASSACHUSETTS, ASSIGNOR OF ONE-I-IALF TO DAVID A. BARBER, 0F BROOKLINE, MASSACHUSETTS.

PORTABLE GRINDER.

Application filed. August 9, 1921.

This invention relates to a portable grinder and has for its object to provide a grinder of this character with which internal grinding can'be performed upon the work, which may be stationary or rotated.

To this end the machine is provided with a tool carrying spindle, mounted within an eccentric sleeve which in turn is mounted Within an outer eccentric sleeve, which carries means for turning the inn-er eccentric sleeve into different positions with relation to the outer eccentric sleeve to thereby in crease or decrease the throw of the spindle with relation to its longitudinal axis or center.

Provision is made for driving the outer eccentric sleeve independently of the spindle, and provision is also made for enabling the spindle to be rotated while the eccentric sleeves are stationary.

These and other features of this invention will be pointed out in the claims at the end of this specification.

Fig. 1 is a plan view of a portable grinder embodying this invention.

Fig. 2, a side elevation with partsin section of the machine shown in Fig. 1 looking toward the left.

Fig. 3, an opposite side elevation of the machine.

Fig. 4, a section on the line 4- 1, Fig. 1, through the eccentrics, with the spindle in elevation.

Fig. 5, a transverse section on the line 55, Fig. 4, and

Fig. 6, a detail in end elevation of the eccentrics.

Referring to the drawings and especially Fig. 4, 10 represents a spindle to which a grinding wheel or toolll such as now cominonly used, is secured. The spindle is mounted to rotate in ball bearings 12, herein shown as three in number and distributed at the center and opposite ends of an eccentric sleeve 13, Whose inner circumference is concentric with relation to the spindle 10 and whose outer circumference is eccentric thereto as shown in Fig. 6. The sleeve 13 contains spacing sleeves 14 for the ball bearings 12 and is closed at its ends by caps 16, which are screwed into the ends of said eccentric sleeve. The eccentric sleeve 13 is mounted to rotate in an eccentric sleeve 17 whose inner circumference is eccentric to the spindle and engages the outer circumference Serial No. 491,026.

of the sleeve 13 and whose outer circumference is concentric with the spindle. The eccentric sleeve 17 will be hereinafter designated the outer eccentric and the eccentric sleeve 13 the inner eccentric. The outer eccentric 17 is mounted to turn in split bearings 18, 19 attached to a plate 20, which is adjustably secured to an upright 21 extended from a supporting plate/22 provided in the present instance with a dovetailed tongue 23. The inner eccentric 13 is provided on its outer circumference with worm gear teeth 24:, see Fig. 5, which are engaged with a worm 25 carried by the. outer eccentric 17, and by a collar 26 affixed to said out er eccentric. By turning the worm 25, the inner eccentric 13 is rotated with relation to the outer eccentric 17 so as to increase or decrease the throw of the spindle 10 with relation to its normal axialcenter and there'- hy vary the orbit in which the spindle moves. The outer eccentric 17 is positively driven by means of a gear 30 fast thereon and meshing with a pinion 31 on a shaft 32 having bearings in lugs or ears 33, 34 on the bearing hubs 18, 19. The gear 30 is secured to the outer eccentric 17 by ascrew 35, which passes through the outer eccentric and engages the inner eccentric to secure the two eccentrics together so as to rotate as a unit in the adjusted position of the eccentrics. A cushioning plug 300 of brass or relatively soft metal is interposed between the screw 30 and the inner eccentric. When it is desired to adjust the inner eccentric to vary the throw of the spindle 10, the screw 35 is disengaged from the inner eccentric and the latter is turned by the worm 25 and worm gear 24 into the desired position, and when in this position, the screw 35 is turned up to engage the inner eccentric and connect it with the outer eccentric as a unit and thereby obtain a more accurate adjustment of the eccentrics, inasmuch as lost motion due to back lash of the worm 25 and worm gear 24 is avoided.

It will thus be seen that when the inner eccentric 13 is adjusted with relation to the outer eccentric 17 and is secured thereto by the screw 35, both eccentrics rotate as one piece, the outer eccentric 17 revolving in its bearing hubs 18, 19 in a true circular path and the center of the inner eccentric revolving in an orbit with relation to the longitudi nal axis of the outer eccentric, and therefore the spindle 10 carried by the inner eccentric travels in said orbit, and while the spindle is traveling in the desired orbit, it is also independently rotated on its own axis, which may be effected in any suitable manner, and in the present instance said spindle is driven from the shaft 40 of a motor 41 by a pulley 42 on the motor shaft, belt 43 and pulley 44 on the spindle 10, see Fig. 1. The motor 41 is suitably mounted on the upright 21 of the supporting member or plate 2:2 and may be provided as shown with a plate 45, which is,

secured in fixed relation to the upright mem ber 21 on the side thereof opposite to the plate 20.

The plateQO is slidably engaged with the upright member 21 by means of a dovetailed tongue on the plate 20 extended into a dovetailed slot 40 in the upright member 21, as shown in Fig. 1.

The plate 20 may be adjusted on the upright member 21 by. a threaded rod 120 which engages a nut 47 fitted into a recess in the plate QOand fastened thereto, the nut 47 being represented as provided with a stem 122 which is extended through ahole in the plate 20 and riveted thereto, (see Figs. 2

and 3).

The threaded rod 120 may be provided with a head or thumb piece 123 for turning the same, which head rests on a cap plate 124 (see Fig. 1) resting on and secured to the upright member as by screws 125. i

The shaft 32 which drives the eccentric 18, 17 as a unit is driven from the motor shaft 40 by means of a worm gear 47 on the motor shaft 40, which meshes with a worm 48 on a shaft 49 supported at one end in a frame 50 which is mounted to turn on themot-or shaft. The worm shaft 49 is'pro'vided at its other end with a worm 51, which is splined thereto to slide thereon and is positioned by a frame 52 on the worm shaft 49. The worm 51 meshes with a worm gear 53 on the shaft 32 and is capable of being disengaged from the gear 53 by the operator'lifting the outer end of the shaft 49, which is permitted by the frame 50 turning on the motor shaft. The frame 52 supports the outer end of the shaft 49, and is itself supported by the shaft 32, upon which is loosely mounted a bolt 64 a which is extended through the frame 52 and is provided with nuts 62, 63, which engage the opposite surfaces of the top portion of the frame. The eyebolt 64- constitutes a support for the frame 52, and by adjusting the nuts 6:2, 63, on the eyebolt. the frame 52, the worm 51 and the free end of the shaft 49 may be raised and lowered with respect to the shaft 32 so as to disengage the worm 51 from the worm gear '53, and to again engage the same.

Then the worm 51 is thus disengaged, the

motor and the eccentrics remain stationary bearings by screws 60.

Provision is made for taking upslack in the belt 43 which drives the spindle 10, and to this end the belt has cooperating with itan idler pulley 55 which is carried by a lever 56, mounted on a pivot pin 57 carried by the bearing hub 19,, said lever being provided with an arm 58 which is connected by a spring with the back plate 20, see Fig. 8.

The portable grinder herein shown is capable of being used for all kinds of internal grinding with the work rotating or station- 3 arv. All kinds of internal or external thread QJ-"nding with. absolute precision can be done with it. It will'do a limited amount of ex l grinding and cutter grinding. Tt'can is mounted on a bench, bench plate or suriace plate and internal grinding can be done without the use of any other tool.

By clamping it to the face of the cylinders of a motor vehicle, the cylinders can be reground without removing the motor from the car, as it is only necessary to remove the cylinder heads and pistons.

One embodiment of the invention is herein shown, but it is not desired to limit the invention to the particular construction shown.

Claims: V g

1. In a machine of the character described, in combination, a rotatable tool carrying spindle, a sleeve in which said spindle is mounted to rotate therein, and whose inner circumference is concentric with said spindle and whose outer circumference is eccentric thereto, a second sleeve within which said spindle carrying sleeve is mounted to turn therein, and whose inner circumference is eccentric and in engagement with the eccentric outer circumference of the spindle carrying sleeve, and whose outer circumference is concentric with relationto said spindle, split hearings in whichsaid outer sleeve is mounted to turn therein, a worm gear on said in ner sleeve, a worm carried by said outer sleeve and meshing with said wormgear to enable the inner sleeve to be rotated with relation to said outer sleeve, and thereby 12 vary the throw'of the spindle with relation to its normal axis, a pinion in mesh with said gear, a shaft mounted on said bearings substantially parallel with said spindle, means for securing said sleeves together in their adjusted positions to rotate as a unit, means for rotating said sleeves,

g I and means for rotating said spindle indeeccentrics 13, 11, are disconnected from the pendently of said sleeves.

2. In a portable grinding machine, in combination, a grinding unit including a spindle and means for imparting an orbital movement to said spindle, a frame having a vertical member on which said grinding unit is mounted, a driving unit-including a motor mounted on said vertical member, means for connecting said motor with said spindle, and separate means for connecting said motor with the means oi the driving unit which imparts orbital movement to said spindle, said latter connecting means having provision for disconnecting the motor from the driving unit.

3.111 a portable grinding machine, in combination, a supporting l'rame having a horizontal member providedwith means for attachment to a lathe and having an upright member, a grinding unit mounted on one side of said upright member and vertically adjustable thereon and having a grinding spindle horizontally arranged, said unit having means for rotating said spindle and means for imparting an orbital movement thereto, a driving unit secured to the said upright member on the opposite side thereof and provided with means for rotating said spindle and with means for rotating the orbit producing means of said grinding unit.

4. In a portable grinding machine, in combination, a spindle for carrying the grinding element, an outer eccentric sleeve, an inner eccentric sleeve within said outer sleeve and in which the spindle is mounted, a split bearing in which the outer eccentric sleeve is mounted having provision for clamping the outer eccentric sleeve in fixed relation thereto to hold the eccentric sleeves stationary, a lug on said split bearing, a shaft carried by said lug and arranged substantially parallel with said spindle, gears connecting said shaft and outer eccentric sleeve for rotating the latter when unclamped from said bearing, and means for rotating said spindle.

5. In a portable grinding machine, in eombination, a supporting frame, a driving unit mounted on said frame and comprising a motor, a grinding unit mounted on said frame and comprising a spindle, and means for imparting an orbital movement to said spindle, means connecting said motor with said spindle to rotate it, and means for detachably connecting the motor with the orbit-imparting means.

In testimony whereof, I have signed my name to this specification.

CHARLES F. lVAITE. 

